*auto-zoom*

The initial default value is t, which causes a :zoom after moving to a new frame with the
top-level commands :dn, :up, :top and :bottom.

If the value is nil, then there will not be an automatic zoom after moving
to a new frame with any of those commands.

If the value is :current, then the top-level
commands :dn, :up, :top, :bottom and :find, will print only the current
frame.

If the value is an integer n, then the top-level commands
dn, :up, :top, :bottom and :find, will print n
frames. Setting *auto-zoom* to an integer will not affect
the number of frames :zoom shows
(see the :zoom keyword
argument count).